Prior art

I will now identify the most relevant prior art for US patent 8686562 based on the provided patent text and a USPTO search.

Most Relevant Prior Art for US Patent 8,686,562

The Google Patents page for US8686562B2 lists "Patent Citations (11)". I will go through the four explicitly listed US patent citations from that section to provide the requested details.

1. US5902129A

• Full Citation: US5902129A, "Process for forming improved cobalt silicide layer on integrated circuit structure using two capping layers"
• Publication/Filing Date: Publication date: 1999-05-11; Priority date: 1997-04-07
• Brief Description: This patent describes a process for forming an improved cobalt silicide layer on an integrated circuit structure using two capping layers. This involves depositing a cobalt layer, a first titanium nitride capping layer, and a second capping layer (e.g., TEOS oxide) over the cobalt. The structure is then annealed to form cobalt silicide, and the capping layers are removed. The first titanium nitride layer acts as a nitrogen diffusion barrier during the silicidation anneal.
• Potential Anticipation (35 U.S.C. § 102): This patent potentially anticipates aspects of Claims 1 and 13 of US8686562 related to the use of a refractory metal nitride (specifically TiN) as a capping layer in an electrical contact structure. While US5902129A focuses on silicide formation and different underlying layers, the fundamental concept of using TiN as a capping layer in a semiconductor device fabrication process could be considered. However, US5902129A does not specify the refractory metal nitride forming the top of the electrical contact, nor does it necessarily teach the specific thickness requirements relative to a bottommost layer as claimed in US8686562.

2. US20060027840A1

• Full Citation: US20060027840A1, "Monolithic integrated enhancement mode and depletion mode field effect transistors and method of making the same"
• Publication/Filing Date: Publication date: 2006-02-09; Priority date: 2003-11-24
• Brief Description: This patent application describes monolithic integrated enhancement mode and depletion mode field-effect transistors (FETs) and methods for making them. The abstract indicates a focus on structures that include both types of FETs, often utilizing different gate stack designs for each.
• Potential Anticipation (35 U.S.C. § 102): This reference appears more focused on the integration of different FET types and their respective gate structures, rather than the specific material composition and arrangement of a refractory metal nitride capped electrical contact as claimed in US8686562. It may generally relate to semiconductor device fabrication and electrical contacts within that context, but it doesn't immediately suggest anticipation of the specific capping layer structure and material defined in Claims 1 and 13 of US8686562. Without a more detailed review of its content, it's difficult to pinpoint direct anticipation of the specific claims of US8686562 related to the refractory metal nitride capping.

3. US20090309228A1

• Full Citation: US20090309228A1, "Method for forming self-aligned metal silicide contacts"
• Publication/Filing Date: Publication date: 2009-12-17; Priority date: 2006-05-01
• Brief Description: This patent application describes methods for forming self-aligned metal silicide contacts. The processes involve depositing a layer of refractory metal or alloy over exposed semiconductor regions, followed by a reaction to form self-aligned silicide. The abstract also mentions using an intermetallic layer as a silicide-forming material and subsequent selective etching.
• Potential Anticipation (35 U.S.C. § 102): Similar to US5902129A, this reference is focused on the formation of self-aligned metal silicide contacts. While it involves refractory metals, the core inventive concept of US8686562 revolves around a refractory metal nitride capping layer specifically and its characteristics. This reference might touch upon general refractory metal usage in contacts, but it does not appear to directly disclose an electrode stack with a capping layer consisting only of a refractory metal nitride forming the top of the contact, with the specific thickness requirement as outlined in Claims 1 and 13 of US8686562.

4. US20100258912A1

• Full Citation: US20100258912A1, "DOPANT DIFFUSION MODULATION IN GaN BUFFER LAYERS"
• Publication/Filing Date: Publication date: 2010-10-14; Priority date: 2009-04-08
• Brief Description: This patent application describes methods for modulating dopant diffusion in GaN buffer layers. It focuses on controlling dopant distribution within GaN-based semiconductor structures, particularly for devices like HEMTs.
• Potential Anticipation (35 U.S.C. § 102): This reference appears to be primarily concerned with the doping profiles and buffer layers within GaN semiconductor devices. It is less directly related to the specific structure and materials of electrical contacts themselves, particularly the refractory metal nitride capping layer as defined in US8686562. Therefore, it is unlikely to directly anticipate Claims 1 or 13 of US8686562.

The analysis above focuses on the explicit US patent citations provided. For a comprehensive prior art analysis, one would typically examine all cited references (including foreign patents and non-patent literature) and perform broader searches for similar technologies. The prompt specifically asked for citations for 8686562, and the Google Patents result clearly lists these under "Patent Citations".